PCI: Rename retval to ret

Rename 'retval' to 'ret' in pci_assign_unassigned_bridge_resources().

Link: https://lore.kernel.org/r/20241216175632.4175-16-ilpo.jarvinen@linux.intel.com


Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Xiaochun Lee <lixc17@lenovo.com>